What was found
ON TAXI OUT, FLIGHT ATTENDANT NOTICED A RUBBER ODOR IN MID-CABIN. IN ADDITION, PARKING BRAKE HANDLE HAS DIFFICULTY RELEASING IT TOOK EXCESSIVE POWER TO INITIATE TAXI. FINALLY RECEIVED AN ANTISKID/AUTOBRAKES STATUS MESSAGE. ON ACFT ARRIVAL ALL MLG TEMP SENSORS HAD NML INDICATIONS. ALL ONES. PERFORMED BITE CHECK ON ANTISKID/AUTOBRAKE LRU AS PER FIM. NO MSGS NOTED. VISUALLY CONFIRMED BRAKES COMPRESSED AND RELEASED NORMALLY. RAN PACKS AND FANS NO ODOR NOTED. ALL TIRES AND BRAKES IN ETOPS CATEGORY 'E': PROBLEMS WITH SYSTEMS CRITICAL TO ETOPS.